Asking for the good of the rain while it falls, and thanking Allah after it.
اللَّهُمَّ صَيِّبًا نَافِعًا
O Allah, make it a beneficial downpour.
مُطِرْنَا بِفَضْلِ اللَّهِ وَرَحْمَتِهِ
We have been given rain by the grace of Allah and His mercy.